NRC Cites Infrastructure Risks from Climate Impacts

Flooded roads and subways, deformed railroad tracks and weakened bridges may be the wave of the future with continuing global warming, a new study says.

Climate change will affect every type of transportation through rising sea levels, increased rainfall and surges from more intense storms, the National Research Council said in a report released Tuesday.

Complicating matters, people continue to move into coastal areas, creating the need for more roads and services in the most vulnerable

regions, the report noted.

"The time has come for transportation professionals to acknowledge and confront the challenges posed by climate change and to incorporate the most current scientific knowledge into the planning of transportation systems," said Henry Schwartz Jr., past president and chairman of the engineering firm Sverdrup/Jacobs Civil Inc., and chairman of the committee that wrote the report.

The nation's transportation system was built for local conditions based on historical weather data, but those data may no longer be reliable in the face of new weather extremes, the report warns.

The committee said proper preparation will be expensive and called on federal, state and local governments to increase consideration of climate change in transportation planning and construction.

The report notes, for example, that drier conditions are likely in the watersheds supplying the St. Lawrence Seaway and the Great Lakes. The resulting lower water levels would reduce vessel shipping capacity, seriously impairing freight movements in the region, such as occurred during the drought of 1988.

The report says marine transportation could benefit from more open seas in the Arctic, creating new and shorter shipping routes and reducing transport time and costs.

The report was prepared by the Transportation Research Board and the Division on Earth and Life Studies of the National Research Council. The groups are part of the National Academy of Sciences, an independent agency chartered by Congress to advise the government on scientific matters.

Government Reports Warn Planners on Sea-Rise Threat to US Coasts

The New York Times, March 12, 2008

A rise in sea levels and other changes fueled by global warming threaten roads, rail lines, ports, airports and other important infrastructure, according to new government reports, and policy makers and planners should be acting now to avoid or mitigate their effects.

While increased heat and intense precipitation events threaten these structures, the greatest and most immediate potential impact is coastal flooding, according to one of the reports, by an expert panel convened by the National Research Council, the research arm of the National Academy of Sciences.

Another study, a multiagency effort led by the Environmental Protection Agency, sounds a similar warning on infrastructure but adds that natural features like beaches, wetlands and fresh-water supplies are also threatened by encroaching saltwater.

The reports are not the first to point out that rising seas, inevitable in a warming world, are a major threat. In a report last September, the Miami-Dade County Climate Change Task Force noted that a two-foot rise by the year 2100, the prediction of the United Nations Intergovernmental Panel on Climate Change, would make life in South Florida very difficult for everyone.

But the new reports offer detailed assessments of vulnerability in the relatively near term. Both note that coastal areas are thickly populated, economically important and gaining people and investment by the day, even as scientific knowledge of the risks they face increases. Use of this knowledge by policy makers and planners is inadequate, the academy panel said.

Its time for the transportation people to put these things into their thought processes, Henry G. Schwartz Jr., the chairman of the Research Council panel, said in an interview.

The 218-page academy report was issued Tuesday, and is available at nationalacademies.org.

Noting that 60,000 miles of coastal highways are already subject to periodic flooding, the academy panel called for policy makers to survey vulnerable areas roads, bridges, marine, air, pipelines, everything, Dr. Schwartz said and begin work now on plans to protect, reinforce, move or replace on safer ground. Those tasks will take years or decades and tens of billions of dollars, at least, he said.

We need to think about it now, said Dr. Schwartz, a member of the National Academy of Engineering.

The multiagency report, a draft assessment, is intended to help policy makers do just that. The 800-page draft was posted online last month for public review at climatescience.gov/Library/sap/sap4-1/public-review-draft. It focuses on the area from Montauk Point on Long Island to Cape Lookout, N.C.

Produced by a collaboration among agencies that included the United States Geological Survey, the National Oceanographic and Atmospheric Administration and the Department of Transportation, the report offers three estimates for sea-level rise by 2100: about 16 inches a century, a rate it said has already been exceeded; about two feet, an estimate many scientists regard as optimistic, and up to three feet, which the report says would be catastrophic for wetlands and other coastal features but that is less than high estimates suggested by more recent publications.

The academy report cited similar estimates.

The multiagency report cited as an example the Port of Wilmington in Delaware. The report says that if the sea level rises by two feet or even a bit less, 70 percent of port property will be affected.

Meanwhile, it says, such a rise in sea level would leave almost 2,200 miles of major roads and almost 900 miles of rail lines in Maryland, Virginia, North Carolina and the District of Columbia at risk for regular inundation.

The academy report made similar points, noting, for example, that airports in many large coastal cities are built in tidal areas, often on fill, making them particularly vulnerable. In the New York metropolitan area, NewarkLibertyInternationalAirport and La Guardia Airport are especially at risk, Dr. Schwartz said.

Some experts have suggested that additional fill could keep pace with rising water, just as many beaches are kept alive today with periodic infusions of sand pumped from offshore. But S. Jeffress Williams, a coastal expert at the geological survey and an author of the multiagency report, noted in an interview that necessary quantities of high-quality fill might not be available where they were needed. In that case, he said, policy makers would have to consider constructing immense systems of coastal armor or accept the need for strategic retreat.

As a first step, the academy report said, transportation officials must realize that climate patterns that prevailed in the past may no longer be a reliable guide for future plans. Instead, it said, they should incorporate climate change into their plans for capital improvements, maintenance schedules, emergency preparedness and so on.

The panel also recommended changes in the National Flood Insurance Program, a federally subsidized program for coastal properties. The report said the maps the program used in setting rates did not reflect the influence of climate change.